Entrained flow Co-gasification of torrefied biomass and coal

In this study, the effect of blending selected torrefied biomass and lower-rank coal samples on entrained flow co-gasification is experimentally investigated, and the results are compared with entrained flow gasification of coal samples. Three biomass samples were torrefied in a lab-scale torrefaction system to obtain a coal-like structure, coherent with the selected coal samples. 275 °C and 40 min were selected as the best-suited torrefaction condition for blending with the coal samples. Four 1:1 coal-torrefied biomass blends were prepared considering the ash and grindability properties for entrained flow co-gasification. The gasification simulations were carried out with Aspen HYSYS to assess the effect of the process conditions. The entrained flow gasifier with 15 kW capacity was built and operated between 1500 °C and 1200 °C with three coals and their four blends. The experimental results show methane (>1300 °C gasification temperature) and tar-free syngas composition. The results of entrained flow co-gasification experiments indicate higher cold gas efficiencies, better syngas quality, and carbon conversion with torrefied biomass blending compared to entrained flow gasification of coal samples. Co-utilization of coal and biomass can be part of a short to medium-term contribution to energy, waste, and global climate change problems.